Effects of Different Forms of Nicotine on Susceptibility to Pesticide of Spodoptera litura Fabricius and Relative Enzyme Activity in it

The susceptibilities of 3-instar larvae of Spodoptera litura Fabricius,which were fed on diet containing nicotine and nicotine salt of different concentrations,to AucaNPV,Fipronil and Spinosad were studied,and the activities of CarE,GST and AchE in different treated larvae were also determined.The results showed that nicotine and nicotine salt could improve the susceptibility of the larvae to Fipronil and Spinosad,while the susceptibility to AucaNPV was slightly affected.Both nicotine and nicotine salt could obviously restrain CarE activity and improve GST activity to a certain extent,while their effects on AChE activity were not significant.